I use hash tables quite a bit and with the impending arrival of PowerShell 3.0 I expect even more so. PowerShell v3 allows you to define a hash table of default parameter values. I'm not going to to cover that feature specifically, but it made me realize I needed a better way to export a hash table, say to a CSV file. So I put together a few functions to do just that.<\/p>\n
To walk you through them, here's a simple hash table.<\/p>\n
I want to export this to a CSV file, but because PowerShell is all about the objects, I want to be sure to get the type information as well. Otherwise when I go to importing, everything will be a string. Here's what I can expect to export:<\/p>\n Key Value Type That looks good. I can take this command and run it through Export-CSV which gives me this file:<\/p>\n #TYPE Selected.System.Collections.DictionaryEntry Perfect. Later, I will need to import this file and recreate my hash table. I can use Import-CSV as a starting point.<\/p>\n Key Value Type Good so far. All I need to do is create a hash table and add each entry to it. I could do something like this:<\/p>\n
\n$hash=@{Name=\"jeff\";pi=3.14;date=Get-Date;size=3 }
\n$hash
\nName Value
\n---- -----
\nName jeff
\npi 3.14
\ndate 2\/2\/2012 10:04:54 AM
\nsize 3
\n<\/code><\/p>\n
\n$hash.GetEnumerator() | Select Key,Value,@{Name=\"Type\";Expression={$_.value.gettype().name}}<\/p>\n
\n--- ----- ----
\nName jeff String
\npi 3.14 Double
\ndate 2\/2\/2012 10:05:57 AM DateTime
\nsize 3 Int32
\n<\/code><\/p>\n<\/p>\n
\n\"Key\",\"Value\",\"Type\"
\n\"Name\",\"jeff\",\"String\"
\n\"pi\",\"3.14\",\"Double\"
\n\"date\",\"2\/2\/2012 10:05:57 AM\",\"DateTime\"
\n\"size\",\"3\",\"Int32\"
\n<\/code><\/p>\n
\nPS C:\\> import-csv hash.csv<\/p>\n
\n--- ----- ----
\nName jeff String
\npi 3.14 Double
\ndate 2\/2\/2012 10:05:57 AM DateTime
\nsize 3 Int32
\n<\/code><\/p>\n